Revert: all refactor commits migrating from Bun.file() to Filesystem module

Author: thdxr

.opencode/skill/bun-file-io/SKILL.md

@@ -0,0 +1,42 @@
+---
+name: bun-file-io
+description: Use this when you are working on file operations like reading, writing, scanning, or deleting files. It summarizes the preferred file APIs and patterns used in this repo. It also notes when to use filesystem helpers for directories.
+---
+
+## Use this when
+
+- Editing file I/O or scans in `packages/opencode`
+- Handling directory operations or external tools
+
+## Bun file APIs (from Bun docs)
+
+- `Bun.file(path)` is lazy; call `text`, `json`, `stream`, `arrayBuffer`, `bytes`, `exists` to read.
+- Metadata: `file.size`, `file.type`, `file.name`.
+- `Bun.write(dest, input)` writes strings, buffers, Blobs, Responses, or files.
+- `Bun.file(...).delete()` deletes a file.
+- `file.writer()` returns a FileSink for incremental writes.
+- `Bun.Glob` + `Array.fromAsync(glob.scan({ cwd, absolute, onlyFiles, dot }))` for scans.
+- Use `Bun.which` to find a binary, then `Bun.spawn` to run it.
+- `Bun.readableStreamToText/Bytes/JSON` for stream output.
+
+## When to use node:fs
+
+- Use `node:fs/promises` for directories (`mkdir`, `readdir`, recursive operations).
+
+## Repo patterns
+
+- Prefer Bun APIs over Node `fs` for file access.
+- Check `Bun.file(...).exists()` before reading.
+- For binary/large files use `arrayBuffer()` and MIME checks via `file.type`.
+- Use `Bun.Glob` + `Array.fromAsync` for scans.
+- Decode tool stderr with `Bun.readableStreamToText`.
+- For large writes, use `Bun.write(Bun.file(path), text)`.
+
+NOTE: Bun.file(...).exists() will return `false` if the value is a directory.
+Use Filesystem.exists(...) instead if path can be file or directory
+
+## Quick checklist
+
+- Use Bun APIs first.
+- Use `path.join`/`path.resolve` for paths.
+- Prefer promise `.catch(...)` over `try/catch` when possible.

packages/opencode/src/cli/cmd/tui/thread.ts

@@ -3,12 +3,10 @@ import { tui } from "./app"
 import { Rpc } from "@/util/rpc"
 import { type rpc } from "./worker"
 import path from "path"
-import { fileURLToPath } from "url"
 import { UI } from "@/cli/ui"
 import { iife } from "@/util/iife"
 import { Log } from "@/util/log"
 import { withNetworkOptions, resolveNetworkOptions } from "@/cli/network"
-import { Filesystem } from "@/util/filesystem"
 import type { Event } from "@opencode-ai/sdk/v2"
 import type { EventSource } from "./context/sdk"
 import { win32DisableProcessedInput, win32InstallCtrlCGuard } from "./win32"
@@ -101,7 +99,7 @@ export const TuiThreadCommand = cmd({
       const distWorker = new URL("./cli/cmd/tui/worker.js", import.meta.url)
       const workerPath = await iife(async () => {
         if (typeof OPENCODE_WORKER_PATH !== "undefined") return OPENCODE_WORKER_PATH
-        if (await Filesystem.exists(fileURLToPath(distWorker))) return distWorker
+        if (await Bun.file(distWorker).exists()) return distWorker
         return localWorker
       })
       try {

packages/opencode/src/lsp/client.ts

@@ -147,7 +147,8 @@ export namespace LSPClient {
       notify: {
         async open(input: { path: string }) {
           input.path = path.isAbsolute(input.path) ? input.path : path.resolve(Instance.directory, input.path)
-          const text = await Filesystem.readText(input.path)
+          const file = Bun.file(input.path)
+          const text = await file.text()
           const extension = path.extname(input.path)
           const languageId = LANGUAGE_EXTENSIONS[extension] ?? "plaintext"